This MOS, with a period running L 2s L 2s L 2s L 2s L s, has a generator between 1/5edo (240 cents) and 3/14edo (257.143). 4/3 being approximated by +2 generators, the generator is called a semi-fourth. The most salient feature of the semi-fourth interval is that it is an ambiguous 8/7~7/6, or an approximate 15/13 if the scale is viewed as involving factors of 13.